1999

7.9

2010

6.9

2008

7.4

2018

7.6

1996

7.8

2016

7.1

2006

7.5

1976

7.0

1982

7.3

2021

7.0

1973

6.8

1966

7.6

1990

8.1

1991

8.1

1979

7.0

2003

7.6

2009

6.6

1995

6.4

1981

6.5

2020

7.2